Far from 'finished' this has been fun to make. I took an idea and played with it. When I stopped playing I let it go even though I could have tweaked and re-worked it to achieve a much better result. That would not have been at all playful - it would have been a battle and it seems that there is more to be learned from the play than the battle. I've argued this for many years on behalf of the 7 - 11 year olds that I worked with when I was teaching, so why has it taken so long to apply it to myself??????????????